Sulfonated polymers derived from L-lysine

ABSTRACT

Modified L-lysine polymers are provided consisting essentially of recurring units of the formula:   and recurring units of the formula:   the total number of recurring units of formula (I) being n and the total number of recurring units of formula (II) being m such that n + m is greater than 50 with the proviso that m can be zero, in which each R radical which may be the same or different, represents one of the following groups: -NH-SO3H: -NH-(CH2)p-SO3H in which p is 1 to 4 ; -NH-(CH2)2-COOH; -NH-CO-CH2-CH2OH; -NH-CO(CH2)2-SO3H; -NH-CO-NH2;   -OH and - N(CH3)2. These polymers have better physiological properties than mixtures of L-lysine polymers with other poly( Alpha -amino acids) and than copolymers of L-lysine and other Alpha -amino acids.

United States Patent [1 1 [4 1 Sept. 23, 1975 Margraff et al.

[ 1 SULFONATED POLYMERS DERIVED FROM L-LYSINE [75] Inventors: Rodolphe Margraff, Ris-Orangis;

Guy Bourat, Bourg-la-Reine, both of France [73] Assignee: Rhone-Poulenc S.A., Paris, France [22] Filed: Apr. 30. 1973 [21] Appl. No.: 355,407

[30] Foreign Application Priority Data FOREIGN PATENTS OR APPLICATIONS 1,188,013 4/1970 United Kingdom 834.227 5/1960 United Kingdomv 822,192 10/1959 United Kingdom 1,221,469 2/1971 United Kingdom 1.218.879 1/1971 United Kingdom 721,067 12/1954 United Kingdom OTHER PU BLlCATlONS Chemical Reactions of Polymers, Fettes, 1966 pp. 373-376. 377. 389-391, 465, 407, 472-473.

Primary Examiner-Howard E. Schain Attorney, Agent, or FirmStevens. Davis, Miller & Moshcr [57] ABSTRACT Modified L-lysine polymers are provided consisting essentially of recurring units of the formula:

(em). m R

and recurring units of the formula:

the total number of recurring units of formula (1) being n and the total number of recurring units of formula (11) being m such that n m is greater than 50 with the proviso that m can be zero, in which each R radical which may be the same or different. represents one of the following groups: NHSO -,H: N-

-OH and N(CH These polymers have better physiological properties than mixtures of L-lysine polymers with other p01y(a' amino acids) and than copolymers of L-lysine and other a-amino acids.

5 Claims, No Drawings SULFONATED POLYMERS DERIVED FROM L-LYSINE The present invention relates to poly(modified L- lysines).

The very diverse physiological properties of basic a-aminoacid polymers have been known for several years, especially as a result of the original work by KATCHALSKY inthisfield'lt is now known that amongst thehomopolymeric poly(basic a-aminoacids),

derived from natural'u-aminoa'cids, poly(L-lysineyin which the NH group in thee-position is separated from the polypeptide chain by 4 methylene groups, possesses, relative to the polymers which 'carry the NH, group closer to the chain, the stericconfiguration for :which the. variouszphysiological effects are the most marked. These effects relate especially to: 1

a, the inhibitition of the enzymatic activity of pepsin ovenavery yide pH range, particularly for pH s as g -the interaction with plasma albumin, W t h. the @prhplexing of natural and artificial nucleic acids with ahistone-mimetic effect, the inhibition of the sy nthesis of 'ribonucleicacid and the control of the chromosome functions of the living cell,

. the inhibition, of the growth of influenza and smallpox viruses and of Newcastle virus and the protection in vivo of mice and monkeys againstpoliomyelitis virus,

j. the inactivation of bacteriophages such as the coliphages T2, and T5, i

k; an anti-tumor effect with inhibition or EHRLIC tumour and'adenocarcinoma TA3, a i

l, the inhibition of the growth and agglutination of numerous microorganisms with, consequently, a bacteriostatican'd bact'e'ricidal'effect, i

m. the complement fi'xation,

n. the blood anti-coagulating activity by inhibiting the formation ofthrombin coupled with an antiheparin effect and l I 0. an aggregating activity towards thrombocytes.

It is knownthatthe intensity and, sometimes, the direction ofthe properties wh en opposing effects coexist iare closely connectedvwith the presenee and the arrangement ofithe' NH- groups which appear on' the outside ,of the; poly( L-lysine molecule, this latter ar- ,rangenient being related to helicoidal shape due to hydrogen bonding between the hydrogen atomsand oxygen atoms of adjacent peptide links which appear under certain experirrientalconditions.

'A number of the abovementioned" properties can be 60 l electively mbdified, decreased, elinlln'atedior reversed when poly(L lysine')""is accompanied by suitable amounts of poly(asparticacid)brpoly(glutarnic acid), which provide carboxyl groups with the opposite electrical charge to that of the e-amine groups of poly(ly-' sine). However; the physiological effects resulting from the non-stoizhiometric neutralisation of the electrical charges are very sensitive to the ionic strength of the medium since salt solutions inte'rpose themselves between the chains of the two polymers and counterbal mice the effects originating from the polyelectrolyte character of the polypeptide complex.

Likewise, certain properties vary when the carboxyl groups are provided by the copolymerisation of L- lysine with an a-aminoacid possessing a nth-carboxyl group (glutamic acid bi" aspar tic'acid) but, in this case, the properties connected with the helicoidal nature of the polypeptide ch'ain are disturbed by the presence of different units scattered throughout the chain; in effect, if it is considered thatthe'a'ppe'arance of ionic groups at'the outside of th 'e' molecule'is closely related tothe helicoidal form of the molecule, it can be seei'i'that the uniformity of' this helix has a great influence on the structure of the molecule,'but by modifying the sidechain Nl-l 'groiips of poly(-L l'ysinefi in desired propor- "tions, by using essentially su'rface chemical reactions so as to provide antagonistic groups. Amongstthe possible 1 reactions, the most advantageous are those which make it possible to introduce either-negativecharges due to sulphonic acid or carboxylic acid groups, either retaining or eliminating the basicity of the nitrogen; or hydrophilic groups which make itpos'sible to vary-the amphipathiccharacter of the molecule.

According to the present invention there is provided an L-lysincpolymer consisting essentially ofrecurring units of the'formula: 1 e

andrecurring units forniirlaz i the total-number ofrecurring of forinu ialj l) being, n and the total number of recurringunits of forsar'ne or different, represents:

,mula (-ll) being msuch that n m is greater than 50,

preferably greaten.than,2,000, itb eingpossible for m to be, zero, in which each R radical, ;w hichmay be. the

. appear from the Examples given below; analogous pro- The various groups-R can be formed on the molecule of poly(L-lysine), by applying any known method for converting a --Nl l group into one of these groups Thus, for example, ,the amino group can be sulphonated to give an ;NHSQ,H group by reaction with an appropriate sulphonati ng agent such as a pyridinesulphuric anhydride complex and it can be converted group by reaction witha .sultone or B-sulphopropionic anhydride, respectively. An NH(CH,),COOH group can be produced by. reaction with B-propiolactone under acidic conditions while under basic conditions the NHCOCH CH,OH group can ,be..produced. An -NHCONH can be produced by reactionwith an inorganic isocyanatel'while an groupcan produced by reaction with S-methylisothiouronium;sulphate. The -NH group can be substituted by two methylgroups, for example by reaction of the polymer with formaldehyde and formic acid. The amino group can'be converted into a hydroxyl group with nitrous acid using, for example, sodium nitrite and hydrobromic acid. Further details of these processes cedures can, ofcourse, be used.

The nature and the relative proportions of the 'vari- .ous groups R can be, adjusted in -such away as to provide the desired physiological effect, it being possible tointroduce each group independently to a controlled extent," either successively or simultaneously. Furthermore, the poly(L-lysin'e) can 'be of any molecular weight provided it contains more than 50 recurring units.

The polymers obtained according to the present invention, which are soluble in an aqueous medium having ionic strength and acidity corresponding to that of living beings (pH approximately 7.35 and ionic strength approximately 0.150 M with respect to NaCl), have a new type of anticoagulant activity which is opposite to that of products of known structure such as heparinoids or hirudinoids. Moreover, the polymers can be rendered insoluble in the form of granules, films and lacquers by intermolecular crosslinking of groups carried in the e-position, by reaction with an appropriate difunctional compound, or by assisting a reaction of a the groups with'one another. The soluble products can also be fixed-by the samegroups onto surfaces which carry reactive sites in order to impart to the said surface the modified physiologicalproperties described above. Amongst thelatter, the most valuable concern the compatibility of th'e'surfaces produced with' the components mentioned and the proteins and enzymes logical liquids. They can also be used for preparing pharmaceutical compositions containing an appropriate pharmaceutical carrier or diluent which can be used in therapy as anticoagulants, analogous to compositions based on heparin.

The following Examples further illustrate the present invention.

EXAMPLE I Potassium carbonate (2.7 g.) and propane-sultone (1.22 g.) are added to a solution of poly(L-lysine hydrobromide) (with a degree of polymerisation equal to about 4,000 L-lysine units) (2.3 g.) in water (100 cc.).

. After heating for 3 hours at 50C., propane-sultone (a further 1 g.) is added and heating is continued at i 50C". for 8 hoursuThe solution is then dialysed through thus obtained. a

a regenerated cellulose membrane against distilled water 10 litres)*for- 48 hours, and then the polymer is precipitated by adding ethanol and dried. Poly(sulphopropylated Llysine) (1.0 g. consisting of 6 l of units of formula (ll) and 39% of units of formula (I) wherein R is the group of the formula:

1 EXAMPLE 2 The procedure of Example 1 is'repeated using 3.75 g. potassium carbonate; the mixture' is heated for'5 hours at 50C. After dialysis, precipitation and drying,

i poly(sulphopropylated L-lysine) (0.8 g.), consisting of 831% of units of formula (ll) and 17% of uni ts of formula (.I) wherein R is the group of the formulai is obtained;

EXAMPLE 3 Following the procedure of Example 2, after the solution has been heated for 5 hours, K,CO, (,700 mg.) and propane-sultone (1.22 g.) are added to it, the whole is left;at 50C. for. 5 hours; this latter operation is repeated 5 times.

After dialysis, precipitation and drying, completely sulphopropylated poly(L-lysine) (1,.0.g-.), consisting of 100% of units of formula (l)- wherein R is the group B-Propiolactone (95 microliters) is added to a stirred suspension consisting of methylene chloride (50milliliters andly'ophilised poly(L-lysine).base(with a degree of polymerisation of 4,000) (0.385 g.) and the whole is stirredfor 20 hours at 20C. The solid material then filtered ofl, washed with diethyl ether and dried.

product (0.280 g,) is obtained which is stirred for 3 days at ambient temperature'in a 0.1N aqueous solu- ;tion of hydrochloric acid (50 cc.). The solution thus obtained is filtered and then dialysed through a regen- .erated cellulose. membrane against distilled water (10 Iiters). .The portionretained is lyophilised to give, the [L-lysine N-ie-( 2-carboxyethyl )-L-lysine] copolymer (O.l8 'g. which is soluble in water and consists of 72.5% ofiunits of formula-(ll) .HCl and 27.5% of units of formula (I) wherein R is the group NH(CH COOH. EXAMPLE 5 Poly(L-lysine hydrobromide) (with a degree of polymerisation of 4,000) (0.45 g.) is dissolved in distilled water (25 cc.), the solution is cooled in a bath to C. and a N aqueous solution of NaOH (2.15 cc.) is run in dropwise, withstirring. B-Propiolacetone (0.27 cc.) is added and the mixture is stirred at ambient temperature for 90 hours. The solution is filtered and then dialysed through a regenerated cellulose membrane against distilled water (10 liters) for 48 hours; the portion retained is then precipitated by adding methanol, washed with diethyl ether and dried.

The [N-e-(3-hydroxy-propionyl)-L-lysine]-[N-e-( 2- carboxyethyD-L-lysine] copolymer (0.30 g.), which is soluble in water and consists exclusively of units of formula (I), R being the group NH-CO--CH CH- 0H in 75% of the units and the group NH-(CH --COOH in 25% of the units, is thus obtained.

5 EXAMPLE 6 Poly(L-lysine hydrobromide) (with a degree of polymerisation of 4,000) (1.05 g.) is dissolved in dis tilled water (40 cc.), potassium cyanate (0.45 g.) which has been freshly recrystallised from water is added and the whole is stirred for 20 hours at 20C. The solution is dialysed through a regenerated cellulose membrane against distilled water (10 liters) for 48 hours, and the portion retained is precipitated in methanol and dried.

The polymer [L-lysine]-[e-ureido-L-norleucine] (0.7 g.), whichis soluble in water and consists of 25% of units of formula (11) .HBr and 75% of units of formula (1), R being the group Nl-1CO-NH is thus obtained. 1 4

Under the same conditions, after the potassium cyanate has acted for hours, the addition of potassium cyanate (0.45 g.) is-repeated and the mixture is again left for 20 hours at 20 C. After dialysis, precipitation and drying, the. polye-ureido-L-norleucine] obtained contains 100% of units of formula (1), R being the group NHC'ONH EXAMPLE 7 A solution of NaNO 1.0 g.) in water (20 cc.) is

added to a solution of poly(L-lysine hydrobromide) (with a degree of polymerisation of 4,000) (1.045 g.) in a 0.-1N aqueous solution of hydrobromic acid (50 cc.) which has been cooled to 0C.

The mixture is left to'react for 20hours at ambient temperature. The solution is dialysed through a regenerated cellulose membrane against distilled water 20 I liters) for 48 hours, and then the retained portion is precipitated in ethanol and dried.

The [L-lysine][e-hydroxy-L-horleucine] copolymer (0.8 g.), consisting of 12% of units of formula (11) .HBr and 88% of units of the formula (1) with R representing the group OH, is thus obtained.

EXAMPLE 8 Poly(L-lysine hydrobromide) (with a degree of polymerisation of 4,000) 1.254 g.) is dissolved in distilled water (100 cc.).

Sodium tetraborate (Na,B,o,. IOH O) (6 g.) is added to the limpid solution obtained and then the whole is cooled to 0C. and the pH adjusted to 9.8 by adding a 1N aqueous solution of NaOH.

A pyridine-sulphuric anhydride complex (2.0 g.) (prepared according to lnorganic s ynthesis, 11, p. 173) is then added and the mixture is stirred vigorously whilst keeping the temperature at 0C., and the pH at 9.8 by adding a 0.1N aqueous solution of NaOH. The

\ reaction is complete when all the complex has dissolved and when the pH no longer varies.

The solution is filtered and is dialysed through a regenerated cellulose membrane against distilled water (2 X 10 liters) and then againstaN/ 10 aqueous solution of hydrobromic acid 10 liters) and again against distilled water (2 X 10 liters). The product is then concentrated from 320 cc. to 30 cc. by ultrafiltration through an AMICON XM 100 membrane (retaining the particles greater than 10 Dalton) and lyophilised. The [L-lysine]-[e-sulphamino-L-norleucine] copolymer (1.0 g.), consisting of 20% of units of formula (II) and 80% of units of formula (I) with R being NH- SO H, is thus obtained.

EXAMPLE 9 Lyophilised poly(L-lysine) base (with a degree of polymerisation of 4,000) (1.3 g.) is dissolved in formic .until thep H of the ultrafiltrate is 7, the product-is lyophilised.

Poly[e-dimethylamine-L-norleucine] (l g.), consisting exclusively of units of formula (1) with R being N(CH is thus obtained. I

EXAMPLE 10 Following the procedure of Example 8, the pyridinesulphuric anhydride complex (1.2 g.) is added and the mixture is stirred vigorously whilst keeping the temperature at 0C. and the pH at 9.8 by adding 1N NaOH solution.

After 2 hours, the addition of the complex (1.2 g.) is repeated and the temperature and the pH aremaintained as above. After a further 2 hours, pyridinesulphuric anhydride complex (1.2 g.) is added for the third time, giving a total of 3.6 g., and the pH is main tained at 9.8 for 2 hours. The mixture is then left to stand for 15 hours at 0C., and purified as in Example 8 Poly( e-sulphamino-L-norleucine) (1.160 g.), containing of units of formula (I) with R being NHSO H, is obtained.

The absence of lysine radicals is verified by dinitrophenylation according to SANGER, Biochem. J., 39, 507 (1945).

EXAMPLE ll Poly( L-lysine hydrobromide) (with a degree of polymerisation of 4,000) (0.209 g.) is dissolved in distilled water (15 cc.). Sodium tetraborate (Na B O 101-1 0) (0.5 g.) is added to the limpid solution obtained, the whole is then cooled to 0C., and the pH adjusted to 9.8 by adding N sodium hydroxide solution.

. lysine e-( 3-sulpho-propionyl )-L-lysine] B-Sulphopropionic anhydride (13.6 g.), of the .forv mula:

CH,CO

C H -SO,

, prepared according to KHARASCH M.S. et al, J. Am.

n the pH no longer varlecular weight greater than 10 Daltons. The retained portion is diluted with distilled water until the resistivity of the ultrafiltrate is greater than 0 cm.

The retained portion is then lyophilised. The [L- copolymer (0.168 g.), containing 75% of units of formula (II) and Y 25% of units of formula (I) with R representing NH- 25 CO(CH SO H, is thus obtained.

EXAMPLE l2 Poly(L-lysine' hydrobromide) (with a degree of polymerisation of 4,000) (0.209 g.) is dissolved in water 'cc.). Triethylamine (0.3 cc.) is added dropwise with stirring to the limpid solution obtained, whilst cooling to 0C. A white gel is obtained.

Sodium 2 hydrazinocarbonyl-ethane-sulphonate monohydrate (4.16 g.) is dissolved in N-hydrochloric acid (50 cc.) at 0C. Sodium nitrite (3.45 g.) is added in small portions and the mixture is left to react for 30 minutes at 0C. The excess nitrous acid is then'removed under a stream of nitrogen-The limpid solution thus obtained is added to the gel prepared above. The mixture is kept at 0C. for 1 hour with stirring and the limpid solution obtained is left for 15 hours at C., and then adjusted to pH 13 by adding 10 N sodium hydrox- Hydrazine hydrate (6 cc.) and distilled water(9 cc.) are added to the latter product (11.4 g.) The mixture is heated under reflux for 2 hours and then water (20 cc.) and ethanol (75 cc.) are added, whilst keeping the mixture refluxing. The product crystallises after cooling. After filtration and drying, sodium 2- hydrazinocarbonyl-ethane-sulphonate monohydrate (9.3 g.) is obtained.

EXAMPLE 13 [L-Lysine L-homoarginine] copolyme r.

Poly( L-lysine hydrobromide) (with a degree of polymerisation of 4,000) (1.045 g.) followed by sodium tetraborate (Na B O .l0H O) (1.9 g.) are dissolved successively in distilled water (50 cc.) at 20C.

A 1N aqueous solution of NaOH (12.5 cc.) is then poured in dropwise, with stirring. During this addition,

the pH of the solution changes from 9.7 to 10.9., S-Methyl-isothiouronium sulphate (1.0 g.) is added to this homogeneous solution and the whole is heated for minutes at 70C. with stirring.

The solution is cooled to 20C. and ultrafiltered through an ultrafiltration membrane which retains solutes of molecular weight greater than 10 Daltons, di-

luting the retained portion with l0 N sodium hydroxide. solution until the ultrafiltrate no longer contains any bromide ions and then with distilled water until an ultrafiltrate with a resistivity greater than 10 9 cm is obtained. A

On lyophilisation of the retained portion, the [L-lysine]-[L-homoarginine] copolymer (0.825 g.)., consisting of 50% of units of formula (I) and 50% of units of formula (11) with R being ide solution. The product is then purified by ultrafiltra- NH|CINH,

is obtained.

EXAMPLE 14 'The following measurements are made on dog plasma containing citrate, in the presence of increasing concentrations of poly(e-sulphamino-L-norleucine), the preparation of which is described in Example 10. The various data was determined as follows: thrombin time, according to BIGGS R. M. and MAC- FARLANE R. 0., Blood coagulation and its disorders-Blackwell Scientific Publications Oxford QUICK time, according to QUICK A. J. J. Biol. Chem.,

. .109, 73 (1935), and

pho-propionic anhydride (13.6 g.) in anhydrous tet- Cephalin-kaolin time, according to LARRIEU M. J. and WEILLAND C. [Rev. Hemat., l2, 2 (1957)]. By way of comparison, the effect of heparin is investigated on this same plasma, using the same techniques.

The following Table gives the results obtained.

Reaction medium investigated Measured coagulation time (seconds) Regardlessof the technique used, it is found that poly(-sulphamino-bnorleucine) causes a marked lengthening of the coagulation time. The anticoagulant action exerted is, at least partially, of the same type as the action of heparin (action on thrombin).

EXAMPLE 15 Rabbit blood (36 cc.) isco1lected on a 3.8% aqueous solution of sodium citrate (4 cc.) and the whole is centrifuged for 20 minutes at 15C., and at 90 G. The plasma thus obtained, which is rich in platelets, is centrifuged for minutes at C., and at 1,400 G. The

platelet deposit is then washed 3 times with a citrate solution containing glucose (sodium citrate: 760 mg., anhydrous glucose: l mg. and physiological serum: q.s.p. 100 cc.) and finally resuspended in Tyrode liquid (4 cc.), containing glucose and albumin [see KIN- LOUGH RATHRQNE R. L. et aL, J. Lab. Clin. Med.,75, 780 (1970)].

The platelet suspension thus obtained (0.6 cc.) is placed in a spectrophotometer cell, Tyrode liquid (2.4 cc.) is added followed, after stirring for 3 minutes, by physiological solution (0.3 cc.) or by a neutral solution of poly(L-lysine) prepared according to G. D. PAS- EXAMPLE 16 Under conditions similar to those of Example 14, the QUICK time is detennined for dog plasma containing citrate, in the presence of increasing concentrations of [L-lysine]-[Ne-(2-carboxyethyl)-L-lysine] copolymer, the preparation of which is described in Example 4. The following values are obtained:

We claim: l. A modified L-lysine homopolymer consisting essentially of recurring units of the formula:

MAN et al., J. Am. Chem. Soc., 83, 709 (1961) or of poly(e-sulphamino-L-norleucine) (Example 10) in the physiological solution. The optical density at 600 nm is recorded as a'function of time, during the 3 minutes which precede, and during the 10 minutes which follow, the addition of the last reagent.

The following Table summarises the results obtained.

concentration 2.2 g/l At a concentration of 1.1 g/l, poly(L-lysine) thus causes very great aggregation of the platelets. In contrast, po1y(e-sulphamino-L-norleucine) has absolutely no action on these platelets, even at a concentration of and recurring units of the formula:

[CO-CHNH] the total number of recurring units of formula (I) being n and the total number of recurring units of formula (I) being m such that n m is greater than 5 with the proviso that m can be zero.

2. A process for preparing a modified L-lysine homopolymer as defined in claim 1 which comprises reacting an L-lysine homopolymer having more than 50 recurring units with a reagent capable of reacting with an e-Nl-l group of lysine to convert it into an N- HSO;,H.

3. A modified L-lysine homopolymer according to claim 1 in which n m is greater than 2,000.

4. A modified L-lysine homopolymer according to claim 1 which has been cross-linked via the e-position.

5. An article or coating of a modified L-lysine homopolymer as defined in claim 1. 

1. A MODIFIED L-LYSINE HOMOPOLYMER CONSISTING ESSENTIALLY OF RECURRING UNITS OF THE FORMULA:
 2. A process for prepaRing a modified L-lysine homopolymer as defined in claim 1 which comprises reacting an L-lysine homopolymer having more than 50 recurring units with a reagent capable of reacting with an epsilon -NH2 group of lysine to convert it into an -NH-SO3H.
 3. A modified L-lysine homopolymer according to claim 1 in which n + m is greater than 2,000.
 4. A modified L-lysine homopolymer according to claim 1 which has been cross-linked via the epsilon -position.
 5. An article or coating of a modified L-lysine homopolymer as defined in claim
 1. 